Transmission mechanisms for automobiles and other vehicles

ABSTRACT

A transmission mechanism for automotive vehicles or other machines, which comprises a drive shaft, a friction-type, singlestage variable-speed system comprising internally tangent male and female disks adapted to be clamped together by means of a fluid-actuated piston, wherein at least one driving male disk rigid with the input shaft of the variable-speed system is interposed between female disks rotatably solid with a drum adapted to rotate about the axis of said male and female disks, a disk clutch adapted to be engaged by the action of a plate, dog means permitting the change from forward motion to reverse motion of the vehicle, said transmission mechanism being characterized in that the piston for clamping the variable-speed disks is axially movable within the bore of said drum carrying the clutch disks and the driven disks of said variable-speed system, and that said drum is axially movable in relation to said clutch disk clamping plate.

nite States Patent Bouthors et al.

[ Sept. 12,1972

3,530,732 9/1970 Kashihara ..74/199 [54] TRANSMISSION MECHANISMS FORAUTOMOBILES AND OTHER VEHICLES Primary Examiner-Leonard H. GerinInventors: Pierre Bouthors; pp Attorney-Stevens, Davis, Miller & Moshergruaennggrais, both of Billancourt, 57] ABSTRACT A transmissionmechanism for automotive vehicles or [73] Asslgnees' 23: g t othermachines, which comprises a drive shaft, a fricf omo eugeo tion-type,single-stage variable-speed system comprisrance ing internally tangentmale and female disks adapted 22] Filed: Oct. (I, 1970 to be clampedtogether by means of a fluid-aituated piston, wherein at east onedriving male dis rigid [2] 1 Appl' 78'506 with the input shaft of thevariable-speed system is in terposed between female disks rotatablysolid with a [30] Foreign Application Priority Data drum adapted torotate aboutdthe axis of said male and female disks, a disk clutch aapted to be engaged by Oct. 29, 1969 France ..6936037 the action of aplate, dog means permitting the change from forward motion to reversemotion of the vehicle, [52] US. Cl said transmission mechanism beingcharacterized in [5 ..zuigg that the piston for p g the variable speeddisks is [58] Field of Search axially movable within the bore of Saiddrum carrying ed the clutch disks and the driven disks of said variable-[56] 1 Reierences It speed system, and that said drum is axially movablein UNITED E relation to said clutch disk clamping plate.

3,557,636 l/ 1971 Dangauthier .,.....74/199 3,387,5Q7 6/ 1968. DeCoye deCastelet.'{' 4/ 199 X 6 Claims, 3 Drawing Figures 13 j 28 5 A H 25 sZ 21 5s 40 7 s m s i 7 17 n 4 v 1 In 57 12 1, Y 34 35 33 W i x .31 7 fl 1:11

TRANSMISSION MECHANISMS FOR AUTOMOBILES AND OTHER VEHICLES verter, whichconstitutes a far from negligible percenb age of the engine output, evenwhen the converter is operated as a coupling device, since the torquecapacity and characteristic curve of the converter are set once for allby its inherent technology.

Transmission mechanisms are also known which comprise a two-stagevariable-speed system. Now these arrangements are objectionable onaccount not only of the considerable number of movable componentelements but also of the necessity of providing a different regulationof the axial stresses obtaining in the two stages. Another inconveniencecharacterizing these mechanisms is due to their considerable over-alldimensions for the two speed-variation stages must be aligned on acommon axisif it is desired to simplify the gear reduction by shiftingthe driven shaft of the first stage (constituting the driving shaft ofthe second stage) while providing the direct-drive feature.

. Othertransmission mechanisms comprising variablespeed systems areknown wherein a single driving disk is mounted to the crankshaft end andprovided with a friction surface engaging a corresponding surface of adriven disk. In mechanisms of this character the axial stressesnecessary for transmitting the torque are absorbed. by the crankshaftbearings and therefore these bearings must be dimensioned accordingly.On the other hand, the use of a single friction surface reducesconsiderably the torque transmittable the'rethrough.

It is the essential object of the present invention to provide atransmission mechanism free of the inconveniences set forth hereinabove,which permits nevertheless a speed variation through a relatively widerange of reduction ratios while using a single-stage variable speedsystem of relatively reduced over-all dimensions.

It is another object of this invention to use in conjunction with thevariable-speed system a friction clutch permitting of dissipating theenergy corresponding to a start and providing a slipless drive of thevehicle or machine under normal driving conditions.

It is another object of the present invention to providea devicepermitting when the vehicle is still, to change from forward to reverseoperation and vice versa, in spite of a residual rotation of the drivingshaft.

- According to the present invention, the transmission speed system isinterposed between female disks rotatably solid with a drum adapted torotate about the axis of an intermediate or lay shaft in a plane atright angles to the axis of said male and female disks, a disk clutchcontrolled by a fluid-actuated plate, dog means permitting the passagefrom forward operation to reverse operation of the vehicle, ischaracterized in that said fluid-actuated piston causing the mutualdriving engagement of said disks in said variable-speed system isaxially movable in the bore of said drum carrying said clutch disks andthe driven disks of said variable speed system, and that said drum canmove axially in relation to the clutch disk clamping plate.

mechanism comprising a input driving or power shaft, a

single-stage, friction-type variable speed system incorporatinginternally tangent male and female disks adapted to be brought intomutual driving engagement 'by a fluid-actuated piston, wherein at leastone male driving disk solid with said input shaft of the variable Withthis transmission mechanism the space available is utilized under thebest possible conditions.

The fact that the clutch can be released at the level of the variablespeed system located at the crankshaft end affords, when the vehicle isstill, a substantial reduction in the vis inertia of moving parts andthus facilitates thestarting of the engine from cold and the change,when stopped, from forward operation to reverse operation of thevehicle, even when the vehicle engine is running.

Other features and advantages characterizing the present invention willappear from the following description of a typical and exemplary form ofembodiment of the transmission mechanism of this invention given withreference to the attached drawing, in which:

FIG. 1 is a fragmentary longitudinal and diagrammatical axial sectionshowing the mechanism, and

FIG. 2 is a section taken along the line 11-11 of FIG. 1. 7

FIG. 3 is a section taken along line IIIIIl of FIG. 1.

Referring first of FIG. 1, the mechanism illustrated comprises a thermalengine designated generally by the reference letter M and provided witha crankshaft 1 having secured to its output end 2, by means of screws 3,a flywheel 4 provided on its outer periphery with a starter ring gear 5adapted to be engaged by the driving pinion of the starter motor (notshown). Said crankshaft end 2 also carries a splined stub shaft 6secured by means of the same screws 3 and constituting the input shaftof the variable speed device.

Male driving disks 7, 7a mounted on said splined stub shaft 6 and housedwithin a drum 8 are disposed between driven disks 9, 9a and 9b rotatablysolid through external teeth with the drum 8.

A piston 10 is rigid with a hollowed ring 1 1 provided with a seal 12and axially movable within the bore 8a of drum 8. The outer and innerperipheries of this ring 11 engage with their front concentric faces 13,the driven disk 9a. The piston 10 constitutes in conjunction with ring11 a clamping plate which, during the operation of the mechanism, isadapted to clamp the driven disks 9, 9a, 9b and the driving disks 7, 7abetween said ring 1 1 and an end cover 14 of drum 8 which is secured toone end of said drum by means of a circlip 15.

The end of drum 8 opposite to cover 14 carries the driving disksstacking of a clutch the engagement of which is controlled by hydraulicmeans, said clutch being designated in general by the reference letterE.

The clutch E consists of driving disks 16, 16a, 16b rotatably rigid withdrum 8, and of driven disks 17, 17a. These driven disks are rotatablysolid through a plurality of pins 18 with a plate 19 supporting a pinion20. The

driving disks 16, 16a and 16b are clamped between a resilient ring orcirclip 21 and the face 22 of clamping plate 19 which is provided on itsouter periphery with a seal packing 23.

Resilient rings 24, 24a are interposed between the driven disks l7, and17a, and between the face 22 of plate 19, on the one hand, and the disk17a, on the other hand, for a purpose to be described presently.

A tubular extension 25 of clamping plate 19 is journalled in bearings 26and 27, but the plate cannot move axially, Slidably mounted in a ring 28rigid with said tubular extension 25 of plate 19 is the rod a of piston10.

The pinion drives through a chain 29 and a pinion 30 rigid with a layshaft 31 joumalled in bearings 32, 33. One portion of this shaft has cuttherein forward and reverse pinions 34, 35 respectively. These pinions34, 35 are in constant meshing engagement the former with an idle pinion26 carried by a stub shaft 37 and the latter with a reversing gear (notshown) (FIG. 2).

A synchromesh and dog-clutch device designated in general by thereference numeral 38 permits of drivingly connecting the stub shaft 37of either with idle pinion 36 or with a pinion 39 in constant meshingengagement with the aforesaid reversing gear (not shown).

The shaft 37 is joumalled in bearings 40, 41 and is formed with teeth 42meshing with the crown wheel 43 of a differential designated in generalby the reference numeral 44 and comprising planet gears 45 adapted todrive the two axle shafts 46 leading to the driving road wheels of thevehicle.

The bearings 27 and 26 are mounted in a movable structure showngenerally at 47 and comprising a number of members rigidly assembled bys weldings.

This movable structure 47 carries at its end a pair of welded anddrilled lugs or tenons 48, 49 adapted to receive through the medium oftrunnion means 50 the force exerted by a hydraulic cylinder and pistonactuator as shown in FIG. 3, adapted to move this structure 47 angularlyabout the axis x-x' of the lay shaft 31, in order to move the plate 19and its pinion 20 man eccentric position in relation to the stub shaft 6and thus cause the desired speed variation of the transmission.

The movable structure 47 is trunnioned to this end on a sleeve 51mounted in the case 52 of the mechanism.

The piston 10 and plate 19 clamping the former the disks of thevariable-speed system and the latter the clutch disks constitute in thedrum 8 a fluid-filled chamber 53 communicating with a source of fluidunder pressure (not shown) via a slot 54 formed in the ring 28 and alsothrough ducts 55, 56, 57 formed in the structure 47 and sleeve 51, asshown diagrammatically in FIG. 1.

The vehicle may be started from rest by gradually increasing the fluidpressure in chamber 53, thus moving the piston 10 and pressing thedriving disks 7, 7a between the driven disks 9, 9a, 9b of thevariable-speed system and at the same time, due to the axial movement ofthe drum 8 connected to the driven disks, thus gradually increasing thepressure of the driving disks 16, 16a, 16b against the driven disks 17,17a of the clutch and against the face 22 of plate 19. The kinematicchain of the movement follows the path: crank shaft 1, shaft 6, variablespeed system 7, 9, 8, clutch system l6, 17, 19, 20,29, 30, 31, 34,36,38, 37,42, 43, 44, 46, in forward drive, and the path 1, 6, 7, 9, 8, 16,17, 19, pinions and chains 20, 29, 30, shafts and gears 31, 35,reversing gear (not shown), 39, 38, 37, 42, 43, 44, 46, in reverse.

It will be seen that the annular members 24, 24a normally tending tomove the disks 17 and 17a away from each other, and disk 17a away fromthe face 22 of plate 19, afford a relative slippage under startingconditions of the vehicle at the level of the clutch disks. This effectis particularly advantageous for it permits of dissipating between therelatively large surface areas of the clutch disks the energy producedby the frictional contact dur ing the slipping phase of the startingprocedure.

While a single form of embodiment of the invention has been describedhereinabove and shown in diagrammatic form in the attached drawing, itwill be readily understood by those conversant in the art that variousmodifications and changes may be brought thereto without departing fromthe spirit and scope of the invention as set' forth in the appendedclaims.

What is claimed as new is:

l. A transmission mechanism for automotive vehicles or other machines,which comprises a drive shaft, a friction-type, single-stagevariable-speed system comprising internally tangent male and femaledisks adapted to be clamped together by means of a fluid-actuatedpiston, wherein at least one driving male disk rigid with the inputshaft of the variable-speed system is interposed between female disksrotatably solid with a drum adapted to rotate about the axis of anintermediate shaft in a plane at right angles to the axis of said maleand female disks, a disk clutch adapted to be engaged by the action of aplate, dog means permitting the change from forward motion to reversemotion of the vehicle, said transmission mechanism being characterizedin that the piston for clamping the variablespeed disks is axiallymovable within the bore of said drum carrying the clutch disks and thedriven disks of said variable-speed system, and that said drum isaxially movable in relation to said clutch disk clamping plate.

2. Transmission mechanism according to claim 1,

characterized in that said piston and plate intended for clamping thedisks of said variable-speed system and of said clutch respectively formwithin said drum a chamber adapted to receive fluid under pressure.

3. Transmission mechanism according to claim 2 characterized in thatresilient members are disposed between the driven disks of said clutchto permit the slipping and dissipation of the energy developped byfriction when starting the vehicle from rest.

4. A transmission mechanism comprising:

a friction-type, single-stage, variable-speed apparatus comprisinginternally tangent male and female disks, fluid-actuated piston meansfor clamping said disks together, and an input shaft to which at leastone of said male disks, which is a drive disk, is rigidly attached,

a drive shaft connected to the input shaft of the variable-speedapparatus,

an intermediate shaft and a drum adapted to rotate thereabout, said drumhaving said female disks rotatably solid therewith, said driving maledisk in terposed between two of said female disks, and

7 said drum adapted to rotate about the axis of said intermediate shaftin a plane at right angles to the axis of said male and female disks, adisk clutch substantially coaxial with said drum, and adapted to beengaged by the action of a clutch clamping plate, wherein said drumcarries clutch disk and the driven disks of said variable-speedapparatus, and wherein said drum is axially movable in relation to theclutch clamping plate, and

dog means for changing the output from said clutch from a forward motionto a reverse motion.

UNITED STATES PATENT oTTTcE OERTIFICATE Oi CORREOHON Paunm No. 690192Dated September 12, 1972 Inventor(s) -Pierre BOUTHORS et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

The Letters Patent should show the priority date for French application69/36.037 as October 21, 1969 and NOT October 29, 1969.

Signed and sealed this 23rd day of January 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT @OTTSCHALK Attesting Officer Commissionerof Patents FORM PO-1050 (10-69) USCOMM-DC 60376-F'69 U.S. GOVERNMENTPRINTING OFFICE: I989 O366-334

1. A transmission mechanism for automotive vehicles or other machines,which comprises a drive shaft, a friction-type, singlestagevariable-speed system comprising internally tangent male and femaledisks adapted to be clamped together by means of a fluid-actuatedpiston, wherein at least one driving male disk rigid with the inputshaft of the variable-speed system is interposed between female disksrotatably solid with a drum adapted to rotate about the axis of anintermediate shaft in a plane at right angles to the axis of said maleand female disks, a disk clutch adapted to be engaged by the action of aplate, dog means permitting the change from forward motion to reversemotion of the vehicle, said transmission mechanism being characterizedin that the piston for clamping the variable-speed disks is axiallymovable within the bore of said drum carrying the clutch disks and thedriven disks of said variable-speed system, and that said drum isaxially movable in relation to said clutch disk clamping plate. 2.Transmission mechanism according to claim 1, characterized in that saidpiston and plate intended for clamping the disks of said variable-speedsystem and of said clutch respectively form within said drum a chamberadapted to receive fluid under pressure.
 3. Transmission mechanismaccording to claim 2 characterized in that resilient members aredisposed between the driven disks of said clutch to permit the slippingand dissipation of the energy developped by friction when starting thevehicle from rest.
 4. A transmission mechanism comprising: afriction-type, single-stage, variable-speed apparatus comprisinginternally tangent male and female disks, fluid-actuated piston meansfor clamping said disks together, and an input shaft to which at leastone of said male disks, which is a drive disk, is rigidly attached, adrive shaft connected to the input shaft of the variable-speedapparatus, an intermediate shaft and a drum adapted to rotatethereabout, said drum having said female disks rotatably solidtherewith, said driving male disk interposed between two of said femaledisks, and said drum adapted to rotate about the axis of saidintermediate shaft in a plane at right angles to the axis of said maleand female disks, a disk clutch substantially coaxial with said drum,and adapted to be engaged by the action of a clutch clamping plate,wherein said drum carries clutch disk and the driven disks of saidvariable-speed apparatus, and wherein said drum is axially movable inrelation to the clutch clamping plate, and dog means for changing theoutput from said clutch from a forward motion to a reverse motion. 5.The transmission mechanism according to claim 1, wherein said piston andsaid clutch clamping plate for clamping the disks of said variable-speedsystem and of said clutch, form a chamber adapted to receive fluid underpressure within said drum.
 6. The transmission mechanism according toclaim 5, wherein resilient sealing members are disposed between thedriven disks of said clutch for permitting slipping and dissipation ofenergy developed by friction when starting said mechanisM.